Dx I'm suffering through writer's block, so I have to pull out all the stops when it comes to writing habits.
Normally it's music. I have a ton of different playlists, and I have a lot of different character-specific songs I use to get into the mood. x3 With some songs, it's the lyrics that remind me of the character, or the voice, or the attitude, or just the music itself evokes a "feeling" that I associate with the character (or a situation the character is in). Then I have music that is more mood music and can apply to lots of characters and situations. Battle music, background music, lovey-dovey music, silly music...
Um, I'm super music oriented. :B
What also helps get me in the mood is to go back and read finished threads with my characters, to remind me of events that happened, little details, and to get a better feel for the character (and it's just fun to see where they started and where they are now). That often inspires and excites me. xD
When I'm going through writer's block (like now), I have to force posts out. Keep writing no matter what. But that's also the time when I start drawing more and play more video games and read some books. It gets the creative juices flowing more. *playing Tales of the Abyss now, which is helping!*
I also go on cleaning sprees. >_> Cleaning/rearranging my room is therapudic and lets me think. My room is sparkly clean right now. xD
Then of course there's meditation and daydreaming. That always works wonders!